Mineral mining installations

ABSTRACT

A mineral mining installation with telescopic props disposed between a floor beam or frame and a goaf shield. A support linkage is articulated between the shield and the floor beam. The shield carries an advance roof girder which can swing about an axis extending along the mine working. The girder resembles a balance beam which tilts downwardly with its forward end towards a mineral face. A cable is secured to the girder and this cable is guided through the structure to the floor beam. The cable acts to restore the roof girder to a substantially horizontal disposition and the girder pivots in relation to the shield under control of the cable as the shield is raised or lowered to maintain this horizontal disposition. A piston and cylinder unit is connected between the linkage and the floor beam and serves to swing the linkage towards and away from the face. Each of the props has a ball and socket type joint at its head and foot enabling it to cant as the linkage is moved by the unit.

United States Patent 1191 Plevak et a1.

[ MINERAL MINING INSTALLATIONS [75] Inventors: Lubomir Plevak, Lunen; Kunibert Bekcer, Werl; Egon Wojaczek, Bockum-Hovel; Norbert Holken, Altlunen, all of Germany [73] Assignee: Gewerkschaft Eisenhutte Westfalia,

Westphalia, Germany [22] Filed: Jan. 30, 1974 211 Appl. No.: 438,044

[30] Foreign Application Priority Data Jan. 31, 1973 Germany 2304528 Mar. 24, 1973 Germany 2314834 [52] [1.8. CI. 61/45 D [51] Int. Cl. E2ID 15/44 [58] Field of Search 61/45 D; 299/33, 31; 91/170 MP; 248/357 [56] References Cited UNITED STATES PATENTS 3,421,795 1/1969 Heyer et a1. 61/45 D X 3,779,023 12/1973 Koppers 61/45 D 3,830,070 8/1974 Rosenberg et al. 61/45 D FOREIGN PATENTS OR APPLICATIONS 262,050 1970 U.S.S.R 61/45 D 1,503,990 10/1967 France 61/45 D Aug. 12, 1975 1,934,376 3/1970 Germany 61/45 D Primary Examiner-Paul R. Gilliam Assistant Examiner-David H. Corbin Attorney, Agent, or Firm-Sughrue, Rothwell, Mion,

Zinn & Macpeak [5 7 ABSTRACT A mineral mining installation with telescopic props disposed between a floor beam or frame and a goaf shield. A support linkage is articulated between the shield and the floor beam. The shield carries an advance roof girder which can swing about an axis extending along the mine working. The girder resembles a balance beam which tilts downwardly with its forward end towards a mineral face. A cable is secured to the girder and this cable is guided through the structure to the floor beam. The cable acts to restore the roof girder to a substantially horizontal disposition and the girder pivots in relation to the shield under control of the cable as the shield is raised or lowered to maintain this horizontal disposition.

A piston and cylinder unit is connected between the linkage and the floor beam and serves to swing the linkage towards and away from the face. Each of the props has a ball and socket type joint at its head and foot enabling it to cant as the linkage is moved by the unit.

11 Claims, 3 Drawing Figures PATENTE AUG 1 2 I975 SHEET PATENTEDAUGIZIQYB 3,898,845

SHEET 3 Fig.3

j Riv 34 MINERAL MINING INSTALLATIONS BACKGROUND TO THE INVENTION The present invention relates to a mineral mining installation which employs a goaf shield and at least one hydraulic telescopic prop for bracing a girder carried by the shield against the roof of a mine working.

It is known for example from German Patent specification l,937,308 to provide an installation which has props articulated to a shield and to a floor beam so that the props can cant in relation to the floor beam. The shield supports an advance roof support girder and one or more rams act on the props to tilt the latter and effect advancement of the girder. It is possible, under certain adverse conditions, for the prop to be damaged by the ram or by excessive transverse forces imparted to the girder by the roof.

A general object of the invention is to provide an improved installation of this type.

SUMMARY OF THE INVENTION I According to the invention there is provided a mineral mining installation comprising a floor-engaging member which during use of the installation rests on the floor of a mine working near a mineral face, a shield carrying a roof girder, a support linkage pivotably connected to the shield and to the floor-engaging member, at least one hydraulically-operated telescopic prop disposed between the shield and the floor-engaging member and operable, during use, to bring the roof girder into contact with the roof of the mine working and shifting means for swinging the linkage in relation to the floor-engaging member and towards or away from the mineral face.

The shifting means is preferably a double-acting hydraulic piston and cylinder unit pivotably connected to the floor-engaging member on the one hand and to the upper region of the linkage or to the pivot connection between the linkage and the shield on the other hand.

According to a further feature of the invention the roof girder is pivotably supported on the shield so as to pivot about an axis extending generally parallel to the mineral face, the girder being arranged in such manner that the end nearest the mineral face tends to tilt downwardly under the influence of gravity and wherein there is provided a traction means which acts on the roof girder to compensate for said tendency and serves to maintain the girder in a position substantially parallel to the floor-engaging member. The traction means can conveniently take the form of a cable guided within the shield itself between the girder and the floor member.

During operation of the installation the piston and cylinder unit and the prop or props operate in conjunction with one another to bring the assembly composed of the roof girder, the shield and the support linkage into various operating positions. Generally, the movement of the linkage by the unit serves to bring the girder into an advanced or retracted position in relation to the mineral face whilst the prop or props raise or lower the girder. In contrast to the known installation the roof girder cannot transmit transverse forces to the prop or props. Moreover, since the unit which effects tilting of the linkage does not act on the prop but instead on the linkage directly, the prop is no longer liable to be damaged. The installation can be adapted within wide limits to any variation in the thickness of the mineral seam being worked, whilst the roof is reliably supported by the girder adjacent the mineral face. To enable the installation to be used with a variety of seam thicknesses it is desirable to make the support linkage a replaceable item so that linkages of different selected lengths, i.e., heights, can be employed.

The aforementioned cable and its guide means are designed to maintain the roof girder parallel to the floor member under all operating positions of the installation. It is desiteale to provide a device for adjusting the tension in the cable or its length.

In order to protect the pivot connection between the shield and the support linkage there is preferably provided a hydraulic arrangement with at least one device which responds to excessive pressure in either working chamber of the piston and cylinder unit. Such an arrangement can then relieve the unit to shift the support linkage should the pivot connection become subjected to excessive shear force.

The invention may be understood more readily and various other features of the invention may become more apparent from consideration of the following description.

BRIEF DESCRIPTION OF DRAWINGS Embodiments of the invention will now be described, by way of examples only, with reference to the accompanying drawings, wherein:

FIG. 1 is a diagrammatic side view of a mineral mining installation made in accordance with the invention;

FIG. 2 is a diagrammatic side view of a further installation made in accordance with the invention; and

FIG. 3 is a schematic representation of a hydraulic arrangement associated with the installation shown in FIG. 2.

DESCRIPTION OF PREFERRED EMBODIMENTS 7 Referring initially to FIG, 1, the installation has a floor-engaging member 10 which may be in the form of a frame or a beam. A goaf-shield 11 is carried by one or preferably several hydraulically-operated telescopic props 12 which are in turn supported by the member 10. Each prop 12 is connected to the shield 11 and to the member 10 with the aid of ball-and-socket type joints 14, 13 respectively, permitting a certain degree of mobility between these components. The props 12 are designed to cant towards or away from a mineral face 25 of the mine working. The goaf end of the shield 1 1, i.e., the end remote from the mineral face 25, is pivotably connected to a support linkage 15 by means of a pivot pin 17. The linkage 15 is similarly pivotably connected to the goaf end of the member 10 by means of a pivot pin 16.

A double-acting hydraulic piston and cylinder unit 18 is interposed between the floor member 10 and the linkage 15. More particularly, the unit 18 has its cylinder pivotably connected to a bracket 20 provided on the upper side of the member 10 by means of a pivot pin 19. The piston rod 21 of the unit 18 is similarly pivotably connected to the upper end of the linkage 15 by means of a pivot pin 22. The pivot pin 22 is provided in proximity to the pin 17 and it is possible to connect the unit 18 to the pin 17 itself instead of to the linkage 15. The unit 18 serves as a shifting means for the linkage 15 and the shield 11.

At the forward end of the shield 11 nearest the minera] face 25 there is provided a roof girder 23 constituting an advance lining for the roof of the working. The

girder 23 has a depending bracket on its underside which serves to receive a pivot pin 24 used to pivotably interconnect the girder 23 to the forward end of the shield 11. The pin 24 is disposed between the ends of the girder 23 so that a portion of the girder 23 projects towards the face 25 and a portion of the girder 23 projects rearwardly from the face 25. The axis of the pin 24 extends generally parallel to the face 25 so as to form a fulcrum for the girder 23. The forwardlyprojecting portion of the girder 23 is somewhat longer than the rearwardly-projecting portion so that the girder 23 has a tendency to swing about the pin 24 in the direction of arrow 26. In order to limit the amount 'by which the girder 23 tilts in this manner a cable 27 has one end 28 attached to a lug 29 at the underside of the rearwardly-projecting portion of the girder 23. This cable 27 is conducted around a deflector 30 and extends along and within the shield 11 so that it is protected thereby. At the other end, the cable 27 extends around a further deflector 31 and is secured with its end 32 to a lug 33 at the upper side of the member 10. The deflectors 30, 31 can take the form of shaped pieces of sheet material or blocks or rollers or sheaves. It is desirable to provide some device 40 such as a toggle-screw or the like for adjusting the tension in the cable 27.

A longwall scraper-chain conveyor 35 is disposed alongside the face 25 and has a guide, generally designated 36, for slidably supporting a mineral winning machine 37 such as a plough or a loading appliance. A double-acting hydraulic ram 34 is connected between the member 10 and the conveyor 35.

Operation of the unit 18 will cause the linkage 15 to pivot about the pin 16 to move the shield 11 towards or away from the face 25. The props 12 can cant to follow any movement of the linkage 15. The props 12 can extend or retract to swing the shield 11 about the pin 17. In this way the girder 23 can be brought into contact with the roof as depicted by reference B or lowered from the roof as depicted by reference A". As the shield 11 moves from position A to position B the deflector 31 moves to the position designated 31 and the linkage 15 swings through an angle a. The length of the cable 27 and its guidance are such that the girder 23 can pivot through the same angle a in the direction of arrow 26 and is then held by the cable 27. Conversely as the shield 11 moves from position B to position A the linkage 15 swings back again and the cable 27 draws the rear end of the girder 23 downwards in a reverse direction to arrow 26.

In this way the girder can be made to assume a position substantially parallel to the member 10 at any position of the shield 11 and at any length of the props 12. The ram 34 serves in known manner to alternately shift a section of the conveyor 35 or the member 10 and the parts supported thereon.

It is desirable to provide for the easy replacement of the linkage 15. It is then possible to have linkages 15 of different lengths which can be selected according to the thickness of the seam in the face 25 to be worked.

The installation shown in FIGS. 2 and 3 is structurally similar to that shown in FIG. 1 and for convenience like reference numerals are used to denote the same parts. Thus, as previously described props 12 are connected with ball-and-socket joints 13, 14 between a shield 11 and a floor member 10. In this case the shield 11 has end walls which are extended laterally of the working to a greater extent than the shield 11 of the FIG. 1 construction. A support linkage 15 is connected to the member and the shield 11 by means of pivot pins 16, I7. A double-acting piston and cylinder unit 18 is connected between the linkage and the floor member 10 and serves to swing the linkage 15 about the pin 16. A bracket 20 is provided on the upperside of the member 10 and receives a pivot pin 19 connected to the cylinder of the unit 18 and a further pivot pin connected to the piston rod of a double-acting ram 34. As with the ram 34 in FIG. 1, the ram is connected to a longwall conveyor (not shown) disposed alongside the mineral face 25. The linkage 15 has end walls which screen off the unit 18. The outer end of the shield 11 nearest the face is pivotably connected with a pin 24 to a roof girder 23 which can swing about the pin 24. As described previously the girder 23 tends to swing in the direction of arrow 26 in view of its somewhat longer forwardly-projecting portion. A cable 27 has one end 28 secured to the rearwardly projecting portion of the girder 23 and is guided by rollers and/or other guide means through the shield 11. The other end of the cable 27 is secured to the member 10 in the region of the pin 19. The assembly operates in the manner described in connection with FIG. 1. So long as the shield 11 only swings about the pin 17 in the direction of arrow 30 there is no undue stress on this pin 17 but in practice the pin 17 is likely to be subjected to shear stress. For example, the roof H of the working is usually uneven and may well have some form of shoulder 31 against which the girder 23 engages to subject the pin 17 to shear force. Also where the roof converges to some extent a thrust force in the direction of arrow 32 can result, which can have the same effect on the pin 17. The pin 17 is hence vunerable to fracture and preferably the installation is supplemented by the hydraulic system depicted in FIG. 3 which is designed to preclude over stressing of the pin 17.

Referring now to FIG. 3, the cylinder of the unit 18 has two working chambers 35, 38. A pressure-relief conduit 33 is connected to a conduit 36 leading to the chamber and similarly a pressure-relief valve 34 is connected to a conduit 37 which leads to the chamber 38.

A control valve device 39 which can be set to one of three control positions denoted a, b and c is connected to the conduits 36, 37 on the one hand and to a main pressure fluid supply conduit P and a pressure fluid return conduit R on the other hand. With the valve device 39 set to position a the chamber 35 is connected to the return conduit R and the chamber 38 is connected to the supply conduit P via a non-return valve in the device 39. In this position a, therefore, the piston rod 21 of the unit 18 extends to swing the linkage 15 towards the goaf side. Conversely, with the device set to position 0 the chamber 38 is connected to the return conduit R and the chamber 35 is connected to the supply conduit P via the non-retum valve in the device 39. In this position c the piston rod 21 retracts to swing the linkage 15 towards the mineral face A. In the position b of the device 39 the conduits 37, 36 are blocked-off by non-return valves in the device 39 so that the unit 18 locks. The pressure setting of the valves 33, 34 at which these valves open is higher than that of the main supply conduit P and is so designed as to protect the pin 17 from excessive force. Thus if the pressure in either of chambers 35, 38 rises above the response pressure of the valve 34, 33 the pressure is relieved so that the piston rod 21 will extend or retract to reduce the loading on the pin 17.

It is possible to utilize one or more hydropneumatic pressure reservoirs instead of pressure relief valves 33, 34 to achieve the same results.

We claim:

1. A mineral mining installation comprising a member which, during use of the installation, engages on the floor of a mine working near a mineral face; a shield, a roof girder carried by said shield, said roof girder being pivotably supported on the shield so as to pivot about an axis extending generally parallel to the mineral face, the girder being disposed such that the end nearest the mineral face tends to tilt downwardly under the influence of gravity; traction means which acts on the roof girder to compensate for said tendency and serves to maintain the girder in a position substantially parallel to the floor-engaging member, said traction means comprising a cable which is secured to a rear portion of the roof girder and to the floor-engaging member, the cable being guided by guide means along the shield, 21 support linkage, means for pivotably connecting the linkage to the shield and to the floorengaging member, at least one hydraulically operated telescopic prop disposed between the shield and the floor-engaging member and operable, during use of the installation, to bring the roof girder into contact with the roof of the mine working and shifting means for swinging the linkage in relation to the floor-engaging member to effect movement of the shield and the roof girder towards or away from the floor of the mine.

2. An installation according to claim 1, wherein a number of telescopic props are provided.

3. An installation according to claim 1, wherein said prop is connected to the shield and to the floorengaging member with ball-and-socket type joints.

4. An installation according to claim 1, wherein the shifting means is a double-acting hydraulic piston and cylinder unit pivotably connected between the floorengaging member and an upper region of the linkage.

5. An installation according to claim 1, wherein the shifting means is a double-acting hydraulic piston and cylinder unit pivotably connected between the floorengaging member and the pivot connection between the linkage and the shield.

6. An installation according to claim 1, wherein there is provided a device for adjusting the tension in the cable.

7. An installation according to claim 4, wherein the piston and cylinder unit is operably associated with at least one device sensitive to excessive pressure in either working chamber of the unit and adapted to prevent excessive force being imparted to the pivot connection between the shield and the linkage.

8. An installation according to claim 6, wherein the piston and cylinder unit is operably associated with at least one device sensitive to excessive pressure in either working chamber of the unit and adapted to prevent excessive force being imparted to the pivot connection between the shield and the linkage.

9. An installation according to claim 7, further comprising a hydraulic control device for effecting operation of the unit. v

10. An installation according to claim 8 further comprising a hydraulic control device for effecting operation of the unit.

11. An installation according to claim 1, wherein there is further provided a longwall conveyor and a double-acting shifting ram connected between the floor-engaging member and the conveyor. 

1. A mineral mining installation comprising a member Which, during use of the installation, engages on the floor of a mine working near a mineral face; a shield, a roof girder carried by said shield, said roof girder being pivotably supported on the shield so as to pivot about an axis extending generally parallel to the mineral face, the girder being disposed such that the end nearest the mineral face tends to tilt downwardly under the influence of gravity; traction means which acts on the roof girder to compensate for said tendency and serves to maintain the girder in a position substantially parallel to the floor-engaging member, said traction means comprising a cable which is secured to a rear portion of the roof girder and to the floor-engaging member, the cable being guided by guide means along the shield, a support linkage, means for pivotably connecting the linkage to the shield and to the floor-engaging member, at least one hydraulically operated telescopic prop disposed between the shield and the floor-engaging member and operable, during use of the installation, to bring the roof girder into contact with the roof of the mine working and shifting means for swinging the linkage in relation to the floor-engaging member to effect movement of the shield and the roof girder towards or away from the floor of the mine.
 2. An installation according to claim 1, wherein a number of telescopic props are provided.
 3. An installation according to claim 1, wherein said prop is connected to the shield and to the floor-engaging member with ball-and-socket type joints.
 4. An installation according to claim 1, wherein the shifting means is a double-acting hydraulic piston and cylinder unit pivotably connected between the floor-engaging member and an upper region of the linkage.
 5. An installation according to claim 1, wherein the shifting means is a double-acting hydraulic piston and cylinder unit pivotably connected between the floor-engaging member and the pivot connection between the linkage and the shield.
 6. An installation according to claim 1, wherein there is provided a device for adjusting the tension in the cable.
 7. An installation according to claim 4, wherein the piston and cylinder unit is operably associated with at least one device sensitive to excessive pressure in either working chamber of the unit and adapted to prevent excessive force being imparted to the pivot connection between the shield and the linkage.
 8. An installation according to claim 6, wherein the piston and cylinder unit is operably associated with at least one device sensitive to excessive pressure in either working chamber of the unit and adapted to prevent excessive force being imparted to the pivot connection between the shield and the linkage.
 9. An installation according to claim 7, further comprising a hydraulic control device for effecting operation of the unit.
 10. An installation according to claim 8 further comprising a hydraulic control device for effecting operation of the unit.
 11. An installation according to claim 1, wherein there is further provided a longwall conveyor and a double-acting shifting ram connected between the floor-engaging member and the conveyor. 